This invention relates to new and improved reflex light reflectors and new and improved methods for making a variety of different reflex light reflectors. The new reflex reflecting articles of the invention have a layer of microsphere lens elements and an underlying metal layer formed in situ by vapor deposition so as to be a continuous layer but which in fact, as it exists in the product, consists of a multiplicity of non-overlapping patches of metal, each fractionally separated from others sufficiently to render the metal layer highly resistant to electrolytic corrosion. These improved reflectors are ideally useful for highway and advertising signs and markers.
Especially significant are the new methods or processes taught herein. The procedures employed permit reliable and economical manufacture of a variety of reflex reflectors.
Specular reflecting metallic flakes such as aluminum flakes have heretofore been employed as reflectors in reflex-reflecting sheeting. The random and multiple overlapping relationship of the flakes in the sheeting necessarily introduces costly waste of material inasmuch as it is only the outer non-overlapped surface portions of the flakes that perform a useful reflective function therein.
The advantages of metal as a specular reflecting layer have long been recognized; and structures in the prior art have sometimes heretofore employed vapor-deposited metal layers (applied, however, late in the process of manufacture after bead or microsphere bonding). Vapor-deposited aluminum layers in particular have been so employed. The continuity of such vapor deposited layers has contributed to brilliance of reflex reflection, but unfortunately, that very continuity as heretofore employed (without this invention's fractional space separation at cracks) tends to render the vapor-deposited layer highly susceptible to electrolytic corrosion as the sheet material is employed in outdoor highway signs and markers.
A major benefit of the present invention is that the advantages of a continuous in situ vapor-deposited layer of metal as a specular reflector are retained, while the disadvantage of that layer being highly susceptible to electrolytic corrosion is essentially obviated.
Still other benefits and advantages of the invention will be evident as this description proceeds.